Fluency is an important part of research on second language learning, but most research on language proficiency typically has not included oral fluency as part of interactions even though natural communication usually occurs in conversations. The present study considered aspects of turn-taking behavior as part of the construct of fluency and…

In human languages, different speech sounds can be contextual variants of a single phoneme, called allophones. Learning which sounds are allophones is an integral part of the acquisition of phonemes. Whether given sounds are separate phonemes or allophones in a listener's language affects speech perception. Listeners tend to be less sensitive to…

Some listeners exhibit higher sensitivity to subphonemic acoustic differences (i.e., higher speech gradiency). Here, we asked whether higher gradiency in a listener's first language (L1) facilitates foreign language learning and explored the possible sources of individual differences in L1 gradiency. To address these questions, we tested 164…

Speech perception involves fusion of multiple sensory inputs, but fusion is not automatic, likely depending on several external and internal factors (e.g., attention, noise, age). In this study, we exploited a specific paradigm in which a short audiovisual context made of coherent or incoherent speech material is displayed before an incongruent…

Compared to low-variability training, high-variability training leads to better learning outcomes and supports generalization of learning. However, it is unclear whether the learning advantage is driven by multiple talkers or by enhanced acoustic variability across target sounds. The current study addressed this issue in nonnative production…

This study investigated how adult second language (L2) learners of Mandarin Chinese use knowledge of phonological and lexical statistical regularities when acoustic information is insufficient for word recognition. A gating task was used to test intermediate L2 learners at two time points across a semester of classroom learning. Native Mandarin…

Distributional learning is a proposal for how infants might learn early speech sound categories from acoustic input before they know many words. When categories in the input differ greatly in relative frequency and overlap in acoustic space, research in bilingual development suggests that this affects the course of development. In the present…